I read the article with the bias of a practicing physician who spends all his time in an acute care hospital and has been involved with many cardiac arrests over the years. I haven’t caused them, by the way, I have just helped out with their care in one way or the other.

Both sides in this article say the patients were dead, or nearly dead. Or close enough for an organ harvest. Read the paper. I don’t think so.

In the article they “defined clinical death as a period of unconsciousness caused by insufficient blood supply to the brain because of inadequate blood circulation, breathing, or both. If, in this situation, CPR is not started within 5–10 min, irreparable damage is done to the brain and the patient will die.”

Every patient in this study had CPR; most within 10 minutes of their arrest. Everyone had blood delivered to their brain. That is the point of CPR: to provide sufficient blood to the brain and other organs.

It is, as an aside, why the conclusion of the study in the discussion is flawed “If purely physiological factors resulting from cerebral anoxia caused NDE, most of our patients should have had this experience.” Good CPR does not lead to cerebral anoxia Most patients in this study did not have an NDE because they had CPR, so they had blood and oxygen delivered to the brain so they could not have an anoxia mediated NDE.

So the real question is whether patients who had brain anoxia had an NDE, and there is no way to determine that in this paper. CPR by its self is not a good surrogate for cerebral anoxia.

Having a cardiac arrest and being promptly coded does not mean there is insufficient blood and oxygen being supplied to the brain.

CPR has variable efficacy, depending on the both the patient and the experience of the provider. Most of us who have had to be involved with a code know, for example, the horrible sensation of all the ribs cracking when you start CPR on a frail old lady and knowing that the CPR is probably not going to be effective.

AS a result of variable CPR, the time it takes the brain to become anoxic is variable. And you would be surprised at how little oxygen people can tolerate with no discernible dysfunction in their cognition, although you might not want them flying your 747. People come into the hospital all the time with with the amount of oxygen in their blood decreased by 30,40, 50% and can walk and talk.

The point is that during a resuscitated cardiac arrest the ability of the brain to get oxygen can be quite variable and if the CPR is done effectively, the brain gets enough oxygen that it is not damaged.

By the definitions of the paper, nobody experienced clinical death. No doctor would ever declare a patient in the middle of a code 99 dead, much less brain dead.

Picky picky, I know, but having your heart stop for 2 to 10 minutes and being promptly resuscitated doesn’t make you “clinically dead”. It only means your heart isn’t beating and you may not be consciousness. Although the discussion states they were”clinically dead”, it takes a lot more than a short course of no heart beat to be dead in this this day and age. But it sure sounds impressive. So when Dr. Shermer quotes the article as saying the patients were “clinically dead”, they weren’t. They were cardiac arrest patients who all received prompt resuscitation. They were “clinically dead” only if nothing was done to them, which is probably not going to pass the hospital ethics committee.

And that brings up the question as to when you are dead. Dying is a continuum. If your heart doesn’t beat for 15 minutes, you are a goner.

10 minutes? not so much.

5? you will be OK.

1 minute? 30 patients in the study had a deliberate cardiac arrest in the cath lab that lasted less than one minute. Were they dead?

Point is that declaring someone dead if their heart isn’t beating is not so simple and in this study you were dead if you had no pulse and were unconscious. Not a good definition. But good for making a splash.

Was Superman really dead when he was beaten to death by Doomsday? No. He met the criteria of the paper, but he came back.

How about Westley when he was cast into the pit of despair and hooked up to The Machine? Dead? I think not.

That’s the issue, they say the patients were DEAD. But they look at “Near Death” experiences. Were they mostly dead? Completely dead?

All these people had change in their pockets when they left the hospital; they were not dead.

The only case I know where someone was truly dead and mouldering in their grave and came back with a good description of a NDE, or in this case a DE, was Buffy Summers.

But I digress.

The other way you can declare people dead is brain dead, again, not so easy to do. There are many criteria for brain death:

The patient has to have no clinical evidence of brain function by physical examination, including no response to pain and a variety of nerve reflexes that do not work: cranial nerve, pupillary response (fixed pupils), oculocephalic reflex, corneal reflex, and no spontaneous respirations.

They have to be off all drugs that mimic brain death for several days and they cannot have metabolic conditions that mimic death. It is important to distinguish between brain death and states that mimic brain death and most of the patients received either a benzo (valium like drugs) and/or a narcotic.

It’s nice to have flat line EEG’s as well, usually two at least 24 hours apart.

And the patient has to drive 45 in the left lane of the freeway with the left turn signal on. That example is not really considered brain dead. But it should be. There are a lot of people I think I should be able to declare brain dead. But I digress. Again.

Being declared brain dead is a time consuming and detailed procedure, as it should be. This will become important in a moment.

Dr. Shermer at least quotes the paper that the patients were ‘clinically dead” using the papers own flawed definitions. But as we have seen their definition of being clinically dead is an artifice used for the paper but of no clinical or physiological relevance. Dr. Chopra, as best I can tell, just makes stuff up. He states, and the emphasis is his “when there was no measurable activity in the brain, when they were in fact brain dead.”

Nowhere, and I mean nowhere, in the Lancet article do they mention whether, besides being unconscious, neurologic function was assessed and the clinical diagnosis of brain dead was determined.

Brain dead, as we saw, is a condition not made at the time of an arrest but a diagnosis that takes time and the patient has to meet multiple criteria before being declared brain dead. They were unconscious for a short period of time after a cardiac arrest, and that is not the same as no measurable brain activity or being brain dead.

None, that’s none, zero zilch, nada, zippo, empty set, of these patients in this study were brain dead. If they had been brain dead they would have been organ donors then buried, not interviewed. They were unconscious for mostly short periods of time, a state that, if the same as being brain dead, means many college students are dead Saturday nights.

In the discussion of the paper the authors state ”Also, in cardiac arrest the EEG usually becomes flat in most cases within about 10 s from onset of syncope’

They reference an annals of internal medicine article as well as one in the journal Anesthesiology where they put EEG monitors on patients in who were having defibrilators implanted. One of the side effects of having a defibrilator placed is that your heart is often stopped for a period of time or you have a heart rhythm induced called ventricular tachycardia, that is usually fatal but can, to a small degree, perfuse the brain.

That quote is not true. I pulled the articles and read them.

What they showed was slowing, attenuation and other changes, but only a minority of patients had a flat line and it took longer than 10 seconds.

The curious thing was that even a little blood flow in some patients was enough to keep EEG’s normal

To quote the annals “Electroencephalographic changes were variable. Background slowing was usually followed by relative loss of electrocerebral activity. ”

Big difference between that and saying everyone flat lines in 10 seconds.

How long does it take to flat line? If there is zero perfusion, the best I can figure out in talking with the experts around my hospital is more like 20 seconds. That’s with NO perfusion. And the EEG experts tell me that the sensitivity of an EEG for function is more like a one megapixel camera than a 5 megapixel. The brain probably doesn’t start to die until several minutes goes by. In my state an EEG is considered so insensitive it does not have to be included as part of the criteria for determining if someone is brain dead, although we get it anyway, a flat line EEG is only part of the mix.

So there is flat line EEG that occurs acutely when the brain is not getting oxygen and there is the flat line that occurs when the brain is dead and an EEG cannot distinguish between them, only the person at the bedside can do that.

So the quote “in cardiac arrest the EEG usually becomes flat in most cases within about 10 s
from onset of syncope” by the authors of the Lancet article is not supported by the literature they reference.

So that brings up several options. 1) They cannot read. 2) They can read, but they cannot understand. 3) They can read and understand but they can’t write a coherent sentence or 4) They are deliberately making stuff up to bolster their position knowing that few will look up their references.

In medicine and in the medical literature, either you have integrity all the time in everything or everything you do is suspect. That one lie, I mean line, in the article, being so counter to the substance of the articles referenced, means to my mind that the whole article is suspect. You judge a man by the company he keeps.

Dr. Chopra’s analysis that they were flat line and brain dead suffers from the same problems as the authors of the Lancet article. It simply isn’t supported by the particulars of the literature he quotes. So in my mind, Dr. Chopra’s writing has the same options: 1) He can’t read, or doesn’t read, the literature he quotes. 2) He can read, but he cannot understand what he read. 3) He can read and understand but he can’t write a coherent sentence or 4) He are deliberately making stuff up to bolster his position.

I have not read the rest of Dr. Chopra’s oeuvre, so I do not have the information at hand to be able to distinguish which of the above options represents his modus operandi.

Both authors quoted the article correctly as to number of NDE. It depended on how an NDE was defined, hence saying 12% (Shermer) or 18% (Chopra) of patients had an NDE is correct. It depends on how many criteria you include as part of your NDE as an NDE is defined two different ways in the paper,

Also, if you read the discussion, you will find that the authors suspect a selection bias in their study and offer a ‘real’ rate of 10% for NDE, or only 5% of patients if based on the number of resuscitations, as more CPR’s lead to more NDE’s. They also admit in the discussion that their broad definition of NDE’s makes their percentage higher as it is more inclusive. It’s all in how you define NDE.

Dr. Shermer has the intellectual honesty to at least delineate which criteria he used from the study for his percentage. Dr Chopra doesn’t bother to explain why there are two different percentages of NDE in the study, choosing to present the alternative percentage as if Dr. Shermer were misquoting, rather than selectively quoting, the study.

“(The actual figure was 18%, by the way).” I love the snarky way this is said.

On his website Dr. Chopra puts MD after his name, and based on his reading and analysis of the paper, I am suspicious that the MD represents an homage to Maryland. Perhaps he has an affiliation with U of M. Go terrapins. Or has an affinity for Baltimore. I am hence forth to be known as Mark Crislip, OR as I like Oregon so much. But if MD means medical doctor, then he should know better.

If I had a medical student on service do such a sloppy analysis of a paper and make up the conclusions, they would be hard pressed to pass their rotation.

It is doubly ironic as Dr. Chopra refers to Dr. Shermer as having “slipshod reasoning” and ‘misrepresents and distorts… Rupert Sheldrake” and saying “skepticism is only credible when it is not being devious.” Holy Pots, kettles and blackness, Batman.

The only thing this article can say is who in this study population had an NDE and what constituted an NDE.

Nothing can be said as to what causes an NDE, except with the caveat that to quote from the accompanying commentary.

“The investigators report that, at the 2-year follow-up, four of 37 patients contacted to act as controls (i.e., people who had not initially reported an NDE) reported that they had had one. Although these patients represent fewer than 1% of the total sample, they represent over 10% of the 37 patients interviewed with a view to acting as controls. If this subsample is at all representative, it implies that around 30 patients from the sample of 282 who initially denied an NDE would, if they had survived for another 2 years, be claiming that they had had one. ”

Some of the NDE’s were, it seems, implanted memories.

The discussion also greatly exaggerates the conclusions that can be drawn from their data.

“We did not show that psychological, neurophysiological, or physiological factors caused these experiences after cardiac arrest.”

Of course not, as set up the study could not have any reliable data as to causation of NDE’s.

Followed by:

“NDE pushes at the limits of medical ideas about the range of human consciousness and the mind-brain relation.”

I do not see this conclusion from the data in this article. Upon close reading I think the only thing this paper is qualified to determine is a description of who get NDE’s and what patients report. As to etiology of NDE’s, much less mind brain relation, it can say nothing. Their reach exceeds their grasp.

I am not saying NDE don’t happen, and I am certainly not going to disagree with the idea that nearly dying is transformative. It is. It is probably why real NDE have greater effects than lab induced NDE. The knowledge that you are really truly mortal is life altering. Cancer survivors can have the same epiphany with out the cardiac arrest

The devil is in the details. As is so often the case, when you go back and read the original paper and its references, what the paper says and what the paper is purported to say often turn out to be two very different things.

In the end the point counterpoint on the NDE’s was, to my mind, done between two people who may not have really understand the literature, one honestly, the other maybe not so much.

Take home message:

Read the original literature. Remember that what a paper says and what people say it says are not the same thing.

Trust no one. But me. References follow. Now you can read them yourself. Let me know if I got it wrong.

29 thoughts on “Near Death Experiences and the Medical Literature”

Such credulous work begs the question, for me, of why they don’t study long-term coma or vegetative patients who recover.

There’s a continuum between hopeless tissue-damaged Terry Schaivo-like cases and borderline cases where there’s no large-scale cell death but no significant brain activity, either. In the latter situation, patients sometimes regain alertness spontaneously or from new medications.

If NDEs demonstrate a true duality between body and soul, shouldn’t *some* of those patients awaken with extensive knowledge of existence beyond the veil of death? But that’s not what happens; they come back with all the signs of an awareness degraded by the long period of unconsciousness and have to rebuild their rusty personalities anew.

Dr Hall has a good point. NDEs, being only self-reported, may occur any time around the event of (loosely used) clinical death, if at all.
A second question — has anyone ever compared these NDE anecdotes to oxygen toxicity, nitrogen narcosis, carbon dioxide poisoning or carbon monoxide poisoning ?
Just curiosity on my part, but I wouldn’t be too surprised to see some similarities.

I know I’m nitpicking, but stop it, everyone, please, with this “begs the question” thing.

Begging the question is a logical fallacy succintly described by R. T. Carroll of The Skeptics’ Dictionary as follows:

“If one’s premises entail one’s conclusion, and one’s premises are questionable, one is said to beg the question.”

It doesn’t mean “makes me want to ask.”

Again, sorry to carp, but I like reading this blog and this usage is like nails on a blackboard to me. Of course I still get into a lather everytime I hear “point in time,” which I’ve been hearing since Watergate, so I’m a hopeless curmudgeonette. Carry on.

My hypothesis of NDEs is that they are all essentially the same, and that they are the consequence of physiological processes organisms invoke while under near death metabolic stress. Depriving the brain of O2, blood, glucose, etc. all cause a drop in ATP, which triggers ATP compensatory pathways. This is what is known as ischemic preconditioning. NDEs are somewhat different in that they are mental experiences, but I think many of the mechanisms are the same, and for the same evolved function, to enhance survival when under near death metabolic stress.

In the “wild”, the most common cause of near death metabolic stress is being chased by a predator where to be caught is to be killed and eaten. I see the NDE as a survival mechanism to give an increased chance of survival under such circumstances.

When you are being chased by a bear, the most important thing to do is to keep on running, no matter how tired you are, no matter what the energy status of your muscles, no matter what injuries you have, no matter what continuing damage you are doing to your body. If you are caught the bear kills you so any injury short of that is infinitely better than being caught.

I think the same physiological processes that invoke this are also responsible for what is known as the “runner’s high”. I see it not as a new source of energy, but rather the delusion that one is not tired. Manipulating the cognitive processes of the brain and what the organism “feels”, is of trivial difficulty compared to manipulating physiology to reverse the physiological consequences of being fatigued and tired. Invoking a delusional state is very easy. Invoking euphoria so the organism keeps running even while continued damage is occurring is much easier than preventing the damage or healing the damage during that metabolic crisis. I call the Euphoric Near Death state the END state. I see all the reports of euphoria in near death states, or under extreme metabolic stress as being due to this. That includes the euphoria of stimulant abuse, solvent huffing, autoerotic asphyxiation, mania (as in bipolar).

Conceptually, some sort of “emergency” energy source that only comes online under extreme metabolic stress (the likes of which an organism may experience only a few times in their lifetime) would be a very inefficient allocation of resources. From an engineering standpoint, a very rarely used energy source can be extremely inefficient and still have utility. The “overhead” of maintaining an inefficient energy source for the 99.99% of the time that it is not needed is the major “cost” of that energy source. How inefficient it is in the 0.01% of the time it is actually used is inconsequential.

I see cachexia as a mechanism along these lines. During cachexia the organism needs glucose and so muscle it turned into amino acids which are turned into glucose. An organism may consume muscle in a few days that took years to accumulate. If conversion of that muscle to glucose allows survival, that is a great trade-off.

“On his website Mr. Chopra puts MD after his name, and based on his reading and analysis of the paper, I am suspicious that the MD represents an homage to Maryland. […] But if MD means medical doctor, then he should know better.

If I had a medical student on service do such a sloppy analysis of a paper and make up the conclusions, they would be hard pressed to pass their rotation.”

Susan Blackmore’s book “Dying to Live: Near Death Experiences” is a fascinating look at this subject. It “collates theories about near-death experience, challenges the reality of spiritual claims and surveys historical and cross-cultural attitudes toward death.” Written in 1993, so it doesn’t discuss research since that date, but still very valuable.

Deepak Chopra is indeed a medical doctor. He graduated from a prestigious medical school in India before coming to the U.S. From Wikipedia:

He completed his primary education at St. Columba’s School in New Delhi and eventually graduated from the prestigious All India Institute of Medical Sciences. His father, Dr. (Col) K. L. Chopra, was a cardiologist in Mool Chand K. R. Hospital, Lajpat Nagar, New Delhi (India) and served as a lieutenant in the British army. Chopra’s grandfather practiced Ayurveda.[2]

Having graduated from AIIMS in 1969, Chopra emigrated to the U.S. in 1970 with his new bride, Rita, to do his clinical internship at a New Jersey hospital, followed by residency training for several more years at the Lahey Clinic in Burlington, Massachusetts and at the University of Virginia Hospital. He became board-certified in internal medicine and endocrinology.[2] [3]

Formerly the Chief of Staff at Boston Regional Medical Center, Dr. Chopra built a successful endocrinology practice in Boston in the 1980’s. His teaching affiliations included Tufts University and Boston University Schools of Medicine.

However, his cheese slipped off his cracker when he became associated with the Maharishi Mahash Yogi (1980s), and one-time physicist (and US, Natural Law Party, presidential candidate) John Hegelin (“Voodoo Science,” by Bob Park). His MD is no longer a legitimate credential (as I see it); Chopra has gone beyond that realm. One could compare Linus Pauling’s loss of scientific cred.

I remember seeing an intensely bright light in front of me, but it didn’t hurt my eyes. It also didn’t seem to go away as light might during normal blinking. I also remember it being warm, but not hot. In the light, I could see figures moving around and I could hear voices but I couldn’t really make anything out. The one thing I remember most clearly was the feeling of euphoria. I felt very calm, almost sedated, but with a dream-like quality to my perception. It was an impressive feeling and quite comforting. The feeling didn’t seem to last long though and soon went away.

The reality. . .

I awoke from a coma to find I had been in a horrific car accident a few days prior. It was 1983 and I was 14 at the time and an unrestrained, back seat passenger of a stationary car that was hit by an elderly, unlicensed driver doing 80MPH. I suffered severe head injuries, broken femur and tib/fib, neck and arm injuries, and lots of blood loss. Thanks to some outstanding paramedics and fast trauma intervention, not to mention several months in traction and a year of therapy, I survived to be an obnoxious teenager, later a college grad, and a normal (? ) adult.

My take. . .

I always think of my NDE as severe head trauma, deep shock, and who knows what kind of brain chemistry-cocktail resulting from what I had just endured and was still wading through. I figure (from a patchwork of stories told to me) the light and people moving about were the sunlight and the accident survivors and later the EMTs working on me. The warmth was a dulled sense of the hot pavement and even hotter Northern California summer sun. The voices were most likely the shouts of the ambulance and fire personnel shouting at me to remain still while they stabilized me for transport.

Of course, I’m an atheist, a skeptic, and a scientist, so my views of things might seem a little cold and calculating of my whole event. Even as a 14-year-old, I was pretty realistic about life and not at all religious. It could be argued that my survival was a “miracle,” but I just figured I had great help very early in the trauma process, was near a decent trauma hospital, and I was a very healthy and active teenager.

Sounds familiar. . .

A few years after my accident, I saw a talk show where people were talking about their NDEs. I remember listening to them describe precisely the feelings, visions, and situations that I had been through. Only theirs were full of stuff like “I saw angels” or “it was heaven’s bright light” and of course, “I saw all my deceased loved ones around me,” “the hand of god,” etc. I had been through the same life-threatening events as them, though some of there’s were heart attacks, or gun shot wounds, but some were car accidents too, only my interpretation was substantially different. I could EASILY tell my exact same NDE story and throw in woo-woo stuff like angels, dead family members, or talk of “going to the light,” but it’s not what I perceived to have happened. Maybe it did and I’m a poor story teller, and as a scientific person, I’m open to possibilities if they later prove to be true, but for now, I was in shock and heavily concussed.

This seemed like a good place to share my experience. Love this blog – you guys are outstanding!

Mark, you are too generous in suggesting that earned respect endures. My father was a lawyer, and he would never brook even the appearance of disrepute throughout his life; wherever he went (even the supermarket) he was an “officer of the court.” I assume your father did the same, and still deserves respect.

Deepak has abandoned, and run from, respectability for 20+ years. Call me old-fashioned; but I think people who dishonor themselves, and/or their professions, have abandoned respect. IMHO, calling Deepack “doctor” is an insult those who endeavor to practice medicine correctly.

As for honorifics, I am proud that my students called me “Joe.” They knew I was the professor; but they also knew I was approachable. That may be more important in saving lives than it is in organic chemistry.

“As for honorifics, I am proud that my students called me “Joe.” They knew I was the professor; but they also knew I was approachable. That may be more important in saving lives than it is in organic chemistry.”

Ask anyone who’s recreationally tripped on nitrous oxide and there’s a good chance they’ve experienced some variation of the tunnel of light and the singing voices.

It just depends on how badly you want to BS yourself that it’s special. I know lots of trippers who contextualize it as “seeing god” (god must be really busy with all the acid and shroom-heads tugging the hem of his robe saying “d000000d!”) I know other people who contextualize it as “floating in the music.” For some reason the creos are careful not to take ownership of trip/trance experiences – whether they happened to Paul on the damascus road or some LSD-filled guy at Woodstock.

I can’t think how you could do a head-to-head comparison but I’ve talked to people who’ve claimed NDEs and divers/mountaineers who’ve gotten anoxic and it sounds a lot like what the nitrous-heads also report. Could it all be the same thing?

mjranum – Speaking of climbers, it’s been speculated that mystical visions associated with holy mountains in Tibet may have their roots in the experiences and hallucinations associated with oxygen deprivation. It’s interesting to look at the stories we tell ourselves about these experiences. It’s also interesting to look at how people’s beliefs play into their NDE and influence the story they tell themselves about their experience (or the pre-existing beliefs that shape the narrative used to explain the experience).

You would be a much more effective communicator if you weren’t so sarcastic. I appreciate your argument, but it’s not a sign of good doctoring to express yourself with such sarcasm. It’s the sign of a know it all, which is something that doesn’t belong in the art of medicine.

I get way too much postive feedback for my style of writing and speech, so I am unlikely to change.

As to good doctoring and communicating, I have 8 teaching awards from the housestaff and several teachers of the year, I am the only MD to be voted by the non medical staff employee of the month at my hospital and I have been voted by the nurses and doctors one of Portlands Top 300 physicians everytime.

paulperry, to get the full effect of Dr. Crislip you need to listen to his Quackcast. It is quite fun, and when I read what he writes I hear both the voice and tone. Click on his name to get the address. He has also been inteviewed more than once on the Skeptics Guide to the Universe… look on the right hand side for that link.